Can an Impact Wrench Be Used as a Drill? Four Scenarios (One Where It Actually Wins)

I answer some version of the question can an impact wrench be used as a drill about once a month, and I stopped giving a single answer years ago, because there isn't one. Whether it works depends on which tool is actually in your hand — and the industry has done a genuinely terrible job of keeping impact driver and impact wrench separate in everyday usage.

So, before anything else: if there's a 1/4-inch hex collet on the front of your tool, you have an impact driver. If there's a 1/2-inch square anvil with a friction ring or a pin detent, you have an impact wrench. Those two tools are about as similar as a screwdriver and a breaker bar. One of them can drill a rough hole all day. The other one will ruin your bit, your adapter and possibly your fastener, in that order.

Context on why I care: I'm a quality and supplier compliance manager for an industrial maintenance contractor. I approve the tool specs, fastener specs and replacement part numbers that go out to our field crews — roughly 60 SKUs a quarter, or rather closer to 70 in Q4 when we run the annual tool audit. In 2024 I rejected about 18% of first-article submissions, and most of those rejections were for documentation gaps, not broken parts. So I'm professionally biased toward can you prove it over will it fit.

The question actually splits four ways:

• You have a 1/4-inch hex impact driver and you need a rough hole — go ahead.
• You have a square-drive impact wrench and you want to drill — don't.
• You're driving long fasteners, not drilling — the impact is often the better tool, and this is the part most people get backwards.
• The hole or the fastener carries a spec, a torque value or a signature — neither tool is the answer.

Step One: Identify What's Actually on Your Bench

Milwaukee's M18 FUEL naming doesn't help here. FUEL means brushless motor plus the electronics package — it's not a tool category. An M18 FUEL 1/4-inch Hex Impact Driver and an M18 FUEL 1/2-inch High Torque Impact Wrench share a battery platform and a marketing prefix and almost nothing else. Same story in the M12 FUEL line: the 1/4-inch Hex Impact Driver and the 3/8-inch Impact Wrench are different animals wearing the same color scheme.

Look at the nose. That's the whole test, and it takes two seconds.

The spec sheet tells you what's in the box. It doesn't tell you what happens when you put a hex adapter on a high-torque anvil.

Here's the frustrating part of my job: the same conversation, every quarter, about why a crew used the wrong tool on a job that had a tolerance. You'd think a labeled rack and a one-page spec would end it. It doesn't. What finally helped was putting a drill in every truck whether the crew asked for one or not.

Scenario 1: 1/4-Inch Hex Impact Driver, Rough Holes — Yes

Hex-shank drill bits drop straight into the collet; no chuck adapter needed. For pilot holes, cable runs, decking, and anything where within an eighth of an inch is good enough, an impact driver with a hex-shank bit is fine, and often faster than dragging out a drill and a bit index.

Where it goes sideways — I've watched all three of these happen on site:

• No clutch. There's no torque limiting, so the tool keeps hammering until something gives. Usually the bit or the screw head.
• Runout. The hex collet plus the hex shank is a two-part slop joint. The difference in wander is way bigger than the spec sheet suggests, especially past about two inches of depth.
• Small bits snap. 1/8-inch and under, in anything harder than pine, at full trigger — gone. The rotary impact doesn't give the bit time to cut; it just shocks it.

Practical version: feather the trigger, let the bit establish a cut before you let it hammer, and switch to a drill the moment the hole carries a tolerance.

Scenario 2: Square-Drive Impact Wrench — No, With One Narrow Exception

A 1/2-inch square anvil holds sockets. To put a drill bit in it you need a square-to-hex adapter, and that adapter is now the weakest link in a chain that already includes a tool delivering north of 1,000 ft-lb in short bursts. Impact-rated adapters only. A standard chrome adapter will crack, and I've seen one split inside a socket where it stayed jammed for a week.

Beyond the safety issue, you're now stacking runout across three joints, there's no chuck to grip a round shank, and the mechanism is designed to break fasteners loose, not to make holes. The exception: driving lag screws or structural screws with an impact-rated adapter. That's a legitimate use of the tool. It's also not drilling.

Here's the part that doesn't make it onto the spec sheet, and it's the thing I check on every tool we approve: the published max torque figure is measured under specific conditions — fresh pack, specific joint, specific run time. Every extension and adapter between the anvil and the work eats some of it, and delivered torque also falls off as the battery discharges. The number on the box is a ceiling, not a promise.

I think about documentation the same way with everything we buy. We keep a 2,000 psi pressure washer for cleaning pump skids, and when it needs a part, the exploded parts diagram is what tells me which o-ring, which unloader valve, which nozzle is actually orderable — and which discontinued pieces a diagram quietly leaves out. The parts diagram tells you what the machine is made of. It doesn't tell you how it behaves under load. Same rule applies to tools.

Scenario 3: The Case Where the Impact Wins (This Is the Counterintuitive One)

People think you reach for an impact tool because you need more power. In our crews, the opposite is true. We switch to impact when we want less reaction force and less cam-out.

Drive a 6-inch structural screw into engineered lumber with a drill/driver and watch what happens: the tool tries to rotate your wrist, the bit climbs out of the head, and by the fourth screw you're leaning on it with a cammed-out driver bit and a stripped head. The rotary impact mechanism converts that torque into short rotary blows, which changes what you feel at the handle and cuts cam-out substantially. The impact isn't better because it's stronger. It's better because it's politer about how it applies force. The extra torque is a by-product — and it's also exactly why people strip threads with these tools.

This is where the battery platform argument actually lands, minus the marketing. Carrying both a hex impact driver and a drill/driver only makes economic sense if they share packs and chargers. That's the real value of a two-voltage ecosystem like M18/M12 — two tools, one charger, one set of spares in the truck. Nothing more exotic than that.

Scenario 4: When There's a Spec, a Torque Value or a Signature

If anyone has to sign off on the joint, the impact tool is out — not because it can't deliver torque, but because you can't verify what it delivered. Torque from an impact wrench is a function of trigger time, battery state, socket condition and how the operator was feeling that morning. There's no number you can write down.

For those jobs you want a calibrated torque wrench and a record, or an electronic torque wrench with job logging. Some Milwaukee ONE-KEY-enabled tools support target torque configuration and job records — verify current capability against your exact model number before you spec it into a process, because that feature set shifts between generations.

Which reminds me of a rejection from last year. A supplier shipped us a batch of lead-free ball valves — the NL998X series type you'd spec for potable water. The valves themselves were fine. Wetted surfaces were within the lead-free limit set by the Safe Drinking Water Act, which caps weighted average lead content on wetted surfaces at 0.25% (Source: U.S. EPA, epa.gov; verify current requirements there). But two of ten sampling points had no traceable NSF/ANSI 61 documentation behind them. We rejected the batch and they resubmitted. Not a bad valve. An undocumented valve — and undocumented and unusable are the same thing when an inspector is standing next to you.

That's the same failure mode as asking whether an impact wrench can be used as a drill. The question isn't whether it can. It's whether you can show what it did.

How to Tell Which Scenario You're In

Four questions, in order. You'll land in a bucket in about thirty seconds, and if you're on the fence at the end, the default is easy.

1. What's on the nose of the tool? Hex collet means Scenario 1 or 3. Square anvil means Scenario 2 or 3, and never Scenario 1.
2. Does the hole carry a tolerance? Bolt clearance, hinge, bearing seat, anything anybody will measure — that's Scenario 4. Drill it, then torque it to spec.
3. What's the material and the count? Two hundred pilot holes in pine and four holes in half-inch plate are different problems, and neither one is a job for a square-drive anvil.
4. What does a failure cost? A stripped screw head in a fence is thirty seconds and a curse word. A stripped fastener in a $12,000 assembly is a rework ticket, a schedule slip and a phone call. If that number has four digits, the tool you're missing has three.

Bottom line: if you're still undecided, buy the drill. A drill/driver with a clutch and a depth stop costs a fraction of one rework event, and it's the difference between it worked and it worked and here's the record.

And the question I've learned to ask about tools is the same one I ask about every quote that crosses my desk: what's not included? The impact wrench comes with a battery, a charger and a case. It doesn't come with a clutch, a depth stop or a verifiable torque number. Those are the things you're actually buying when you buy the right tool.

Tool specifications and warranty terms referenced here reflect manufacturer-published material as of early 2025. Verify current specs, torque ratings and warranty coverage with the manufacturer before specifying. Pricing varies by retailer and date.